Bending strength dependence of load-to-annual ring direction

2017 ◽  
Vol 48 (8) ◽  
pp. 773-778
Author(s):  
V. Rede ◽  
S. Essert ◽  
Z. Šokčević
Keyword(s):  
Annual Ring ◽  
Bending Strength ◽  
Strength Dependence

Preparation and Characterization of Three Dimensions Chitosan Rods with Biomimetic Layered Structure Similar to Annual Ring

2005 ◽  
Vol 288-289 ◽  
pp. 473-476
Author(s):  
Qiao Ling Hu ◽  
Bao Qiang Li ◽  
Zhong Ming Zhang ◽  
Jia Cong Shen
Keyword(s):  
Layered Structure ◽  
Annual Ring ◽  
Bending Strength ◽  
Chitosan Solution ◽  
Ring Structure ◽  
Three Dimensions ◽  
Concentric Circles ◽  
The Relationship

Inspired by the annual ring structure of wood, a cylindrical semi-permeable chitosan gel membrane was chosen as a template to separate chitosan solution from NaOH coagulation solution. Three dimensions (3D) chitosan (CS) rods (Φ5×80 mm) with layered structure similar to annual ring of wood were prepared via a novel and simple in-situ intermittently precipitating method. These chitosan rods presented quite good mechanical properties with bending strength and shear strength of 102MPa and 31MPa respectively. The concentric circles layered structure was approved by SEM characterization, the mechanism of preparation and the relationship between structure and properties of chitosan rods were also discussed.

scholarly journals Effect of Annual Ring Angles on Static Bending Strength Performances of Cross-Laminated Woods Made with Spruce

2014 ◽  
Vol 42 (3) ◽  
pp. 290-300
Author(s):  
Eun-Jong Sung ◽  
Chang-Bae Kwon ◽  
Hyun-Soo Ryu ◽  
Hee-Seop Byeon ◽  
Han-Min Park
Keyword(s):  
Annual Ring ◽  
Bending Strength

3D Interconnetive Porous Silica Ceramics Prepared by Gel Casting with Egg White Protein as a Foaming Agent

2012 ◽  
Vol 512-515 ◽  
pp. 555-558
Author(s):  
Hai Xu ◽  
Jia Chen Liu ◽  
Ying Na Zhao ◽  
Zhen Guang Hou
Keyword(s):  
Bending Strength ◽  
Porous Silica ◽  
Porous Ceramics ◽  
Egg White ◽  
Foaming Agent ◽  
Egg White Protein ◽  
Gel Casting ◽  
Strength Dependence ◽  
Highly Porous ◽  
Exponential Relation

Highly porous silica ceramics were produced by gel casting with egg white protein (EWP) as a foaming agent and evaluated by measuring the porosity, mechanical strength and microstructure. After drying, the green bodies were debindered and sintered at 1300°C for 4 h. The influences of the EWP content on the open porosity as well as the strength were investigated. The porosity of the obtained porous silica ceramics was within 70.2%-86.1%, the bending strength decreased from 6.81 MPa to 5.48 MPa. It was found that the strength dependence of the porosity was well described by a modified exponential relation of the form σ=σ0exp(-BP), where P is the porosity and B is a constant (B = 1.37 was obtained by fitting the experimental data). This finding is in agreement with other literature data and seems to indicate a common feature of all porous ceramics.

Annual ring orientation effect on bending strength of subfossil elm wood

2016 ◽  
Vol 63 (1) ◽  
pp. 31-36 ◽  
Author(s):  
Vera Rede ◽  
Sara Essert ◽  
Janoš Kodvanj
Keyword(s):  
Annual Ring ◽  
Bending Strength ◽  
Orientation Effect

The ionic strength dependence of chromatin folding

1978 ◽  
Vol 36 (2) ◽  
pp. 220-221
Author(s):  
F. Thoma ◽  
TH. Koller
Keyword(s):  
Electron Microscopy ◽  
Electron Microscope ◽  
Ionic Strength ◽  
Specimen Preparation ◽  
Preparation Technique ◽  
Carbon Supports ◽  
Ionic Strength Dependence ◽  
Chromatin Folding ◽  
Strength Dependence ◽  
Preparation Techniques

Under a variety of electron microscope specimen preparation techniques different forms of chromatin appearance can be distinguished: beads-on-a-string, a 100 Å nucleofilament, a 250 Å fiber and a compact 300 to 500 Å fiber.Using a standardized specimen preparation technique we wanted to find out whether there is any relation between these different forms of chromatin or not. We show that with increasing ionic strength a chromatin fiber consisting of a row of nucleo- somes progressively folds up into a solenoid-like structure with a diameter of about 300 Å.For the preparation of chromatin for electron microscopy the avoidance of stretching artifacts during adsorption to the carbon supports is of utmost importance. The samples are fixed with 0.1% glutaraldehyde at 4°C for at least 12 hrs. The material was usually examined between 24 and 48 hrs after the onset of fixation.

Study Of Structure Formation Of Organic-Mineral Compositions With Fibrous Filler By Electron Microscopy Method

2019 ◽  
pp. 41-47
Keyword(s):  
Electron Microscopy ◽  
Structure Formation ◽  
Mineral Composition ◽  
Bending Strength ◽  
Cement Stone ◽  
Hydrated Cement ◽  
Fibrous Filler ◽  
Organic Mineral ◽  
Microscopy Method ◽  
Mineral Compositions

The article presents the study of processes of structure formation of cement stone and products of hardening of organic-mineral compositions with fibrous filler (shavings) by the electronic scanning microscopy method. It is established that the additive-free cement stone at the age of 28 days has a dense and homogeneous structure, consists of calcium hydro-silicates, Portlandite and calcite - newgrowths characteristic for cement systems. Cellulose fibers, which make up the bulk of the substance of shavings, are sufficiently active, which determines the high adhesion of the hydration products of the cement binder to their surface. It is shown that the introduction of shavings into the organo-mineral composition leads to inhibition of cement hydration processes. Organo-mineral compositions with different shavings content (two compositions) were analyzed. The first composition is characterized by a fairly dense structure, the cement stone consists of globular nanoscale nuclei of hydrosilicates, Portlandite and calcite. The second composition has a loose porous structure, cement stone consists of non-hydrated cement grains, newgrowths are represented by calcite and vaterite. The structure of the contact zone "osprey fiber-cement stone" in the organo-mineral composition of the first composition indicates a good adhesion of the filler surface with the phases of hydrated cement. The use of shavings as a fibrous filler (the first composition) increases the tensile and bending strength, as well as the wear resistance of organo-mineral compositions. The data obtained by scanning electron microscopy are confirmed by the results of studying the processes of structure formation of cement stone by quantitative x-ray phase analysis.

Performance enhancement of normal contact ratio gearing system through correction factor

2019 ◽  
Vol 13 (3) ◽  
pp. 5242-5258
Author(s):  
R. Ravivarman ◽  
K. Palaniradja ◽  
R. Prabhu Sekar
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Correction Factor ◽  
Bending Strength ◽  
Performance Enhancement ◽  
Transmission Ratio ◽  
Contact Ratio ◽  
Element Analysis ◽  
Normal Contact ◽  
Root Region

As lined, higher transmission ratio drives system will have uneven stresses in the root region of the pinion and wheel. To enrich this agility of uneven stresses in normal-contact ratio (NCR) gearing system, an enhanced system is desirable to be industrialized. To attain this objective, it is proposed to put on the idea of modifying the correction factor in such a manner that the bending strength of the gearing system is improved. In this work, the correction factor is modified in such a way that the stress in the root region is equalized between the pinion and wheel. This equalization of stresses is carried out by providing a correction factor in three circumstances: in pinion; wheel and both the pinion and the wheel. Henceforth performances of this S+, S0 and S- drives are evaluated in finite element analysis (FEA) and compared for balanced root stresses in parallel shaft spur gearing systems. It is seen that the outcomes gained from the modified drive have enhanced performance than the standard drive.

Bending Strength of Steel Fibre Reinforced Concrete Ribbed Slab Panel

2018 ◽  
Vol 15 (1) ◽  
pp. 15
Author(s):  
AMIR SYAFIQ SAMSUDIN ◽  
MOHD HISBANY MOHD HASHIM ◽  
SITI HAWA HAMZAH ◽  
AFIDAH ABU BAKAR
Keyword(s):  
Reinforced Concrete ◽  
Bending Strength ◽  
Steel Fibre ◽  
Concrete Slab ◽  
Future Application ◽  
Fibre Reinforcement ◽  
Fibre Reinforced Concrete ◽  
Conventional Concrete ◽  
Steel Fibre Reinforced Concrete ◽  
Bending Load

Nowadays, demands in the application of fibre in concrete increase gradually as an engineering material. Rapid cost increment of material causes the increase in demand of new technology that provides safe, efficient and economical design for the present and future application. The introduction of ribbed slab reduces concrete materials and thus the cost, but the strength of the structure also reduces due to the reducing of material. Steel fibre reinforced concrete (SFRC) has the ability to maintain a part of its tensile strength prior to crack in order to resist more loading compared to conventional concrete. Meanwhile, the ribbed slab can help in material reduction. This research investigated on the bending strength of 2-ribbed and 3-ribbed concrete slab with steel fibre reinforcement under static loading with a span of 1500 mm and 1000 mm x 75 mm in cross section. An amount of 40 kg/m steel fibre of all total concrete volume was used as reinforcement instead of conventional bars with concrete grade 30 N/mm2. The slab was tested under three-point bending. Load versus deflection curve was plotted to illustrate the result and to compare the deflection between control and ribbed slab. This research shows that SFRC Ribbed Slab capable to withstand the same amount of load as normal slab structure, although the concrete volume reduces up to 20%.

Ceramic Materials. Effects of Fracture Origin and Microstructure on Bending Strength of High-Strength Si3N4.

1994 ◽  
Vol 43 (489) ◽  
pp. 599-605 ◽  
Author(s):  
Akira YAMAKAWA ◽  
Takehisa YAMAMOTO ◽  
Tomoyuki AWAZU ◽  
Kenji MATSUNUMA ◽  
Takao NISHIOKA
Keyword(s):  
Bending Strength ◽  
High Strength ◽  
Ceramic Materials ◽  
Fracture Origin
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